<!doctype html>
<html lang="en">
 <head>
  <meta charset="UTF-8">
  <meta name="Generator" content="EditPlus®">
  <meta name="Author" content="">
  <meta name="Keywords" content="">
  <meta name="Description" content="">
  <title>哈哈</title>
	<style>
	
	</style>
 </head>
 <body>
		<div id="box">
			<a href="" id="a">哈哈</a>
		</div>
 </body>
</html>
<script>
	var oBox = document.getElementById('box');
	var a = document.getElementById('a');

	//得到oBox元素内容
	console.log(oBox.innerHTML);
	//设置oBox元素内容 
	a.innerHTML = '李超云'; //会把这个元素里面所有内容全部覆盖
</script>
